Abstract:With the off-site preservation forest 21-year old Larix olgensis in Qinshan forestry centre in Linkou, in Heilongjiang province as the materials, the resources of Baidaoshan were analyzed using SNP molecular markers and he software DNAMAN. There is genetic diversity in L.olgensis. SNP marker has proved the provenance of L.olgensis. Rupr has a wealth of genetic diversity from the molecular level, and the marker indicates that the genetic variation mainly exists within populations, smaller variation exists among population SNP Primers detected of 178 SNPs. It has sequenced a total of 240 EST sequencing, and the successfully are 193 EST sequencing, in which the successful percentage is 80.42%. Using the software DNAMAN analysis the sequencing result found that there are 178 SNPs, 126 belong to transition type, accounting for 70.79% of the total variance; with 52 belong to transversion type, accounting for 29.21% of the total variance, the mutant type roughly in line, transition∶transversion=7∶3. In the transition type, A/G and C/T transition account for 37.08% and 33.71%, respectively; some types of transversion G/C, A/C, A/T, and G/T respectively in 7.87%, 8.99%, 7.87% and 4.99%. But within each family, transition and transversion are quite different, there is no law. The largest proportion of conversion and transversion is No.554 family, a ratio of 7∶1, the smallest pedigree is 855 pedigree with ratio 3∶4.